The present invention relates to hay-making machines for windrowing, comprising at least two rake wheels driven by the energy of a motor vehicle so as to rotate in identical directions about axes directed upwards and situated at an invariable distance from one another, the said rake wheels comprising arms carrying identical working tools, which arms extend substantially outwards and are guided in such manner that their working tools over a partial range of their revolution, pivot upwards and in the direction opposite to the direction of rotation of the said rake wheels. The guiding of the tool carrier arms can be effected for example by a cam fixed on a spindle concentric with the axis of rotation of the rake wheel.
In practice machines having one rake wheel equipped with such a guide principle have proved excellent for windrowing. As the invention relates to a machine comprising at least two rake wheels, obviously the aim is to obtain a machine having a greater working width.
The selection of a machine on which at least two rake wheels are driven in identical directions of rotation has the purpose of obtaining a machine which permits of easy and rapid production of double windrows, that is in two passages of the machine, which is of particular interest especially for cropping aftermaths.
Now in view of the identical directions of rotation of the two rake wheels, known machines of this kind hitherto required a distance between the rotation axes of two rake wheels at least as great as the external diameter of a rake wheel. This characteristic involves losses of fodder between the said rake wheels. This defect can be diminished but not entirely eliminated by significantly staggering one rake wheel in relation to the other, seen in the direction of travel of the machine. This feature involves fresh complications as regards especially the chassis and the carrier wheels.
In another known machine the planes passing through the longitudinal axes of the tool carrier arms of each rake wheel are situated at different distances above the ground. This embodiment involves the use of working tools of different lengths for each rake wheel, which is irksome both for the manufacturer and for the user.
Thus hitherto no machine of this kind has been capable of being produced in large numbers.
It is the purpose of the present invention to provide a windrowing machine as described in the introduction which does not have the above-mentioned drawbacks.